FI78135B - OVER FREQUENCY FOR FOUNDATION. - Google Patents

Description

1 78135

Wire strip and method of making the same

The invention relates to a wire strip, which wire strip comprises S3 a plurality of thermally fastened coils made of single-stranded synthetic yarn, the adjacent coils being inserted into each other so that the loops of one coil penetrate between the loops of the adjacent coil, a filling material that fills the hollow spaces of the coils.

It is desirable to be able to modify the air permeability of wire strips made of artificial material, hereinafter briefly referred to as "wire strips", and to adapt it to the particular application. The wire strip proposed in German application P 29 38 221.6-45 has spirals (coils) open and a very high air permeability. With high-speed paper machines, high air permeability can be a disadvantage because it causes very strong air turbulence, which can interfere with the paper path. The air permeability could be reduced by inserting rigid mono-25 filaments from the edges of the wire into the hollow spaces of the spirals or by drawing a spinning fiber yarn or multifilament yarn with a puller. In this case, however, the retracted material would be drawn straight in the hollow spaces, so that a very large amount of filling material would be required to significantly reduce the air permeability. In addition, a large amount of filler material would increase the basis weight of the wire and thus make it more difficult to retract the filler material and generally work with the wire, especially its installation. Subsequent importation of the filler material into the combined wire 35 presents difficulties and disadvantages; either the filler material n- 2 78135 is introduced into the interconnected spirals either before the heat-sealing of the wire strip or the insertion or retraction of the filler material takes place after the heat-sealing. In both cases, after the filling material 5 has been drawn in, the heat-setting must be carried out a second time, if necessary, because otherwise there is a risk that the filling material will shrink later due to the heat of the paper machine. Double thermal bonding is very expensive. In addition, when the filling material is introduced 10 before the spiral strip is thermally attached, there is a difficulty that the spirals can then move out of place along the still slippery plug wires, as a result of which bumps and bumps may form in the wire strip. In both procedures, the filling material 15 would still have to be pushed further out of the side of the wire strip so that the wire strip is still filled to its full width even after heat setting and shrinkage of the filling material. Such a method would be complex and error prone.

20 Finally, an additional disadvantage is that the filling material enters the spirals straight and can therefore easily slip out of the wire strip. If, for example, the edge of the wire strip is damaged in the paper machine, the filling material can easily stick to the parts of the paper machine and become pulled out of the wire strip. It may also be sufficient for the wire strip to rub sideways onto the parts of the paper machine.

It is an object of the invention to provide a wire strip as mentioned above, the air permeability of which has been reduced.

This object is solved according to the known features of claim 1.

The invention further relates to a method for producing a wire strip according to the invention as set out in claim 3.

Preferred embodiments of the invention are set out in the subclaims.

ti 3 78135 "Filling material outlet length" here means the length that the filling material has in the stress-free state. If the filling material has thermally attached corrugations or arcs, these must be pulled out by subjecting the filling material to low tension before determining the outlet lengths.

The filling material, e.g., multi- or monofilament yarn, spun fiber yarn, or ribbon yarn, is not only in a completely stress-free state in the hollow spaces of the coils, but also stacked and bundled. Since the tension material is not affected by any stresses, it expands strongly in the width direction and then fills the hollow spaces of the spirals better and more evenly than, for example, a wire under tension. In particular, with low twisted multifil-15 yarns and spun yarns as filler, the individual fibers are evenly distributed in the hollow spaces so that there are no open points in the wire strip.

By "ribbon yarn" is meant herein a chemical ribbon (nozzle ribbon or foil ribbon), ribbon ribbon or weaving ribbon. However, the filling material may also have another linear textile shape.

The advantage of the method according to the invention is that the filling material of the hollow spaces of the coils allows the coils to be pushed into each other and can be easily pushed out, whereby the use of the pre-filled spirals in the manufacture of the wire strip becomes possible. The channel to which the plug is guided is formed without great difficulty. When straight drawn mono- or multifilaments are used as the filling material, it would not give way to the channel space when forming the hub space, but the insertion of the spirals into each other would face a considerably high resistance. When such a filling material is used, the filling material could be introduced into the hollow spaces only after the spirals have been joined together.

35 The above-mentioned difficulties which exist if the spirals are filled only after joining do not occur in the manufacture of the wire strip according to the invention. There may be a slight shrinkage of the filler material during thermal bonding of the filled wire strip, but the filler material still has sufficient material-length to accommodate this shrinkage, i.e. even after heat-sealing the wire strip the filler material is not more or less strongly drawn in hollow spaces. This corrugation causes sufficient friction inside the spiral 10 to prevent the filler material from sliding out of the spiral, even when, for example, the edges could be damaged. This is especially important when using a smooth material, for example monofilament, plied monofilament or multifilament.

15 Admittedly, the sliding of the filling material out of the spirals may also be prevented by the material being completely blocked from the inside of the spirals. In practice, however, this path cannot be traversed, since the spiral strips then become very heavy and, moreover, the spirals 20 thus filled can no longer be joined together.

In order to fill the interior of the coils or spirals before insertion into each other, there are in principle two possibilities, namely either the artificial wire is wound around the filling material already during the production of the spirals or the spirals are filled with the filling material after reinforcement, but before joining. Alternatively, the helices can be filled by first drawing one or more smooth monofilament yarns into the spirals and then changing the shape of the filling material by acting on the outside, for example by winding the yarn around the spirals so that the turns of the wire will be between the turns of the spiral and immediately this wire is drawn perpendicular to the longitudinal axis of the spiral. The wire thus draws 35 filling material between the helical turns of some l! 5 78135 outwards perpendicular to the helical axis. The filling material is heat-sealed in this state. Another possibility is that the filling material is formed by gears or by pressing hard from the outside with other spirals. It is also possible to use a yarn consisting of less shrinkable and high shrinkage components. This wire self-detaches during thermal bonding. The same effect is achieved by using dual component straps. The wire strip according to the invention is particularly suitable for paper machines. It is particularly advantageous to use it in the press section of a paper machine.

The invention is described in more detail below with implementation examples. The figures show: Figure 1 hollow spaces filled with stretched straps and hollow spaces filled with non-tensioned material juxtaposed;

Figure 2 is a longitudinal sectional view of opposed coils filled with tensioned wire and spi-20 coils filled with unstressed and corrugated heat-sealed filler material;

Figure 3 shows the filling of the filling material over the spiral arches, the wire of the filling material being particularly long; and Figure 4 shows the production of filled spirals from which a wire strip according to the invention is made.

As described in DE-A-29 29 221.6-45, the wire strip is formed by a large number of spirals or helices, the threads of which adhere to each other and at the same time interleave with each other, and of plug wires, one of which is inserted into a channel formed by two adjacent spirals.

As shown in Figure 1, the hollow space of each spiral is filled with a filling material. The hollow spaces A and B of both left-hand spirals in Fig. 6 78135 1 are then filled with monofilament yarns, while both right-hand hollow spaces C and D are filled with bulky multifilament or spinning fibers. It can be seen that in the hollow spaces A and B there are still open points, e.g. where the helical arcs of the adjacent spirals are toothed with each other, while the space-filling filling material completely fills the hollow spaces C and D.

As can be seen from Figure 2, the filling material not only completely fills the hollow spaces of the spirals, but si-10 also partially joins between the spiral arcs. In this way, the surface of the wire strip becomes closed and smoothed, and the already rather weak marking of the wire strip continues to deteriorate. This also causes an increase in the pressing surface of the wire strip, which causes an improvement in the paper drying.

When the filler wire is particularly long, it can even be caused that the filler material protrudes between the helical arcs, cf. Figure 3. This gives the wire strip a soft surface.

One way of manufacturing a filled spiral is shown in Figure 4. The preparation takes place mainly as described in DE-A-29 38 221.6-45. In addition, the filler wire G is drawn from the spool S through rollers W, the speed of which is adjustable. The spool S and the rollers W 25 are connected to the axis of the pin D and rotate in one piece with the cone K around the longitudinal axis of the pin D and the pin D.

In addition, the spool P of the monofilament yarn from which the spirals are formed is positioned so that the monofilament yarn 30 T enters the cone K at the point P1 in the outer third of the cone K and then slides over the inside of the cone K and finally wrapped around the pin D. The filler material wire G enters the outer circumference of the cone K and at its point P1 is adhered to the inonofilament T, i.e. presses it against the surface of the cone K35. As the monofilament yarn T slides along the inner portion of the cone K, it enters the portion of the filler yarn G between points P1 and P2. The point P2 is located at the junction of the cone K and the pin D, i.e. at the point where the spiral winding begins.

5 By adjusting the speed of the rolls W, the length of the part of the filler wire G that the monofilament wire T takes with it and then is placed inside the coil winding can be adjusted. The filler yarn G is pressed slightly to the side between the monofilament yarn T and the auxiliary yarn H and is fastened in this state by passing it through a heating device. The extra length of the filler wire G is thus fixed, i.e. the extra length of the filler material is used for corrugating it or forming an arc. When the auxiliary yarn H has left the pin D and the spiral has been pushed down from the pin D, the thermally bonded filler yarns G remain inside the spiral and are distributed in its hollow interior.

The bulge length of the filler wire G, as mentioned, is determined by the circumferential speed of the rolls W. The length of the bulge is generally between 1.2 and 8, i.e., the length of the spiral to be filled is 1.2 to 8 times the length of the filler wire. However, lower or higher deflection values are also possible.

In making the wire strip, the filled spirals are pushed laterally into each other so that the coils of the other coil enter the coils of the adjacent coil. The spirals are pushed so far into each other that the spiral arcs form a channel. A plug wire is inserted into this channel, which firmly connects the spirals. Finally, the wire strip is thermally bonded in a stretched state, as a result of which the spirals protrude slightly into the material of the gun wire and give the gun-galle a wavy shape.

As the coils are pushed into each other, the coils of the second coil push the filling material 35 of the second coil out of its way. Since the filling material is very 3 78135 space-wide, it does not cause any excessive resistance and gives way.

The air permeability of the wire strip is determined by the quality of the miru filling material and the length of its filling.

5 For example, a wire strip made of coils with a wire thickness of 0.7 mm and a plug thickness of 0.9 mm and equipped with 20 plug threads per 10 cm and a thickness of 3 2 of 2.5 mm has an air permeability of 320 m / m / min with a pressure difference of 12.7 mm from the water column. If the same wire strip 10 is made of coils filled with two polyamide-multifil yarns, each at 1,300 dtex, with a bulge 3 of 1.5, then the air permeability decreases to 140 m / m / min.

li

Claims (4)

9,781 35 A wire strip for paper machines, for example, which wire strip comprises 5 thermally fastened coils made of single-stranded synthetic yarn, the adjacent coils being inserted so that the loops of one coil penetrate between the loops of the adjacent coil, the connecting element through the channel, a filling material filling the hollow spaces of the coils, characterized in that the connecting element is a plug wire, 15 the coils have no tension spring prestress and dig into the plug wire material in thermal attachment, and the initial length of the filling material in the helix hollow space is greater than the length that the filler material has in a stress-free, non-heat-bonded state. Wire strip according to Claim 1, characterized in that the filling material is a monofilament or multifilament yarn, a spinning fiber yarn or a ribbon yarn. A method of manufacturing a wire strip according to claim 1 or 2, wherein the coils made of heat-sealable synthetic material are inserted into each other such that the coil loops are sandwiched between adjacent coil loops and the interlocking loops of the coils form a channel, the plug is then inserted through the channel in a stretched state so that the coils are slightly dug into the material of the plug wire, characterized in that the inner part of the coils is filled with a filling material before the others are inserted, and 10 7 81 3 5 that the filling material is heat-sealed in the corrugated state. Method according to Claim 3, characterized in that, during the production of the coils, the artificial wire 5 is wound around the filling material. li 11 78135